The present invention refers to a diaphragm valve of the type having a closing lift stop and including a diaphragm which is actuated by a hand wheel via a valve stem.
Manually actuated valves provided with diaphragms of elastomer material and lacking any limitation of the valve lift run the risk that high closing forces may destroy the diaphragm during the closing lift, ultimately resulting in a leaky closure of the valve.
It is known to provide valves with a closing lift stop in form of nut and counternut configuration or in form of a slip-clutch. Both these proposals are however very complicated and uneconomical.